Refining oils



A 1=,622,879 .March 29 1927' H. o. PARKER ,REFINING OILS Filed Jan. 22. 1925 (/nfreafed u INVENTOR #arf/Jon Par/fer www? ATTORNEY `Patented Mair. 29, 1927.

UNITI-:DI STATES PATENT OFFICE.

HARRISON O. PARKER, OF TULSA, OKLAHOMA, ASSIGNOR TO THE MATHIESON ALKALI WORKS, OF NEW YORK, N. Y.,

A CORPORATION OF VIRGINIA.

BEFINING oILs.

Application led January This invention relates to thel refining of hydrocarbons, and includes an improved methodof refining hydrocarbon oils and distillates, particularly light petroleum oils, such as gasoline, and especially casinghead gasoline and natural gas gasoline. The invention also includes an improved apparatus for carrying out the process of the invention.

en gasoline containing substantial amounts of' hydrogen sulfide gas or of other unstable sulfur compounds is stored for some time, these sulfur compounds tend to decompose, perhaps by slow and partial oxidation,

with the formation of elemental sulfur which is dissolved in the oil. This dissolved sulfur makes it very difiicult satisfactorily to refine the-oil after such decomposition occurs. Casinghead gasoline and natural gas gasoline, moreover, have very high vapor pressures, and to prevent unnecessary evaporation losses it is desirable to put such products into permanent storage as quickly as possible after production. In many instances, particularly in the case of isolated plants, the production of casinghead gasoline or of natural gas gasoline While continuous is at a relatively loW rate, and it has been customary temporarily to store such products as produced and periodically to refine the Astored material because the continuous methods of treatment available have been inefiicient and uneconomical when employed on a small scale. For example, it has hitherto been proposed to refine hydrocarbon oils with aqueous solutions containing hypochlorites. The methods commonly piacticed, however, are usually carried out as batch operations and ordinarily invo-lve the separate preparation of the hypochlorite solutions from liquid chlorine or from bleaching powder or in some other suitable Way. Where such refining operations have been carried out 1in a continuous manner, it has been necessary separately to prepare and to store the hypochlorite refining solutions employed.

According to the present invention, the oil to be refined is subjected to treatment with an aqueous hypochlorite solution initially i containing a considerable excess of la caustic 22,- 1925. Serial No. 3,983.

alkali, such as caustic soda, and sufficient chlorine is introduced into the solution, as t-herefining operation continues, to maintain a concentration of hypochlorite therein sufficient to efi'ect the desired refining treatment. As the caustic alkalivis used up it is replaced or replenished so that the refining operation may be carried out in a substantially continuous manner.

The yseparate preparation of the hypochlorite refining solution is thus eliminated, and any necessity for storing the hypochlo-l rite solution is also avoided.- Chlorine is readily available and easily handled as a liquid stored under pressure in steel cylinders and the present invention is particularly advantageous, where liquid chlorine is utilized. The chlorine may be introduced directly, in properly regulated amounts, into the alkaline aqueous solution and after introduction the chlorine combines with the caus` tic alkali therein to form the corresponding hypochlorite. Chlorine gas, however, may, be employed for introduction into the alkaline aqueous solution vto form a hypochlorite therein.

Gasoline products, and particularly the lighter and more volatile gasoline products, may thus be refined and desulf'urized by treatment with a hypochlorite solution in a continuous way, avoiding any decomposition incident to storage of the unrefined oil and avoiding evaporation ,losses due to tempo rary storage of the oil before refining. Vhere the oil to be refined contains appreciable quantities of hydrogen sulfide or other undesirable constituents which will react With caustic alkali, they oil may be subjected to preliminary treatment with an aqueous alkaline solution, such as a solution of caustic soda, to promote economy of the hypochlorite refining solution, and this treatment may also be carried out in a continuous manner. The method of the `present invention is of special value and application Where the production of the oil is continuous but at a relatively low rate, and enables the eflicient and economical. application of hypochlorite refining solutions in a continuous manner in such instances.

t-ower to the bottom of the second and from.

the top of the second to the third and to discharge the oil from the top of the third. Theiir'st two 'towers are charged with the refining solutions and the oil is contacted therewith/as it rises through the towers. The towers in which the preliminary alkali treatment and the hypochlorite refining treatment are carried out are provided with connections for fintroducing fresh caustic alkali solutions and for discharging ithe spent solutions. The tower in which the hypochlorite refining treatment is effected is provided with means for introducing chlorine and for distributing it through the alkaline solution in the tower. The chlorine is advantageously supplied from a' container of liquid chlorine under pressure and 'the amount of chlorine introduced can advantageously be determined for purposes of control by arranging the liquid chlorine container on scales and by weighing the amount of chlorine introduced. The third tower acts as a settling tower for the separation of any refining solution which might be carried along with the oil.

The invention will-be further described in connection with the accompanying drawing which illustrates an apparatus embodying the invention and adapted for carrying out the process of the invention, but it will be understood that this further detailed de-t scription and illustration are for the purpose of exeinplification and that the invention is not limited thereto. The general arrangement of apparatus illustrated in the drawing is of general utility in carrying out the process of the invention. The specific apparatus described in detail in connection with the drawing, however, is well adapted for the treatment 4of about 100 bbls. of gasoline per hour.

(,Referringto the drawing, the apparatus there illustrated comprises three vertical towers, A., B and C, about four feet in diameter and 18 feet high,ofl either welded or riveted construction and tested to about 7 5 lbs. pressure. The first tower A is provided with a 2 pump-in line 1 entering the tower 8 from the base and passing through almost to the opposite vsideof the tower. The section of pipe inside the tower is provialed with 18 cross slits each about 1% in lengthand about l across. From thetop of the tower A a 3 overflow line 2 is arranged to discharge into the lower part of the second tower B. A connection 3 is provided for introducing fresh caustic alkali yer B is provided with eighteen slits having solution into thetower and a connection i is arranged for discharging spent solution from the tower.v sample cock 5 is also provided in the overow line 2. A 3 pipe 6 is arranged entering the second tower B 18 from the bottom' and extending therethrough nearlyvto the opposite side for the introduction of oil into this tower. This pipe is connected to the overflow line 2 through valve 7 and to the pump-in line 8 through valve 9. Pump-in line 1 has valve 10 therein. Lines 1 and 8 are each connected to the pump 11 for forcing -Athe oil to 4be refined through the towers and by yappropriate control of the valves 7, 9 andlO 'the oil may.' be forced through tower A to tower B or directly to tower B. 1

he pipe 6 for introducing oil into the towa total area approximately haf that of the s its in line l. A connection 12 is provided for introducing fi'esh caustic alkali solution into tower B and a connection 13 is arranged for discharging spent solution from the tower. An overtiow line 14 is arranged. for discharging oil from the u per end of the tower into the tower C. sample cock 15 is provided in the line 14. A l extraheavy perforated pipe 16 is arranged in the bottom of the tower B for the introduction of chlorine. This pipe is connected 'to the liquid chlorine container 17 successively through a cast iron check valve 18, a cast iron globe valve or plug cock-19, a cast iron check valve 20, an expansion valve 21, an expansion coil 22 and a needle valve 27 on the container 17. The liquid chlorine container 17 is arranged inverted in a frame 23 Isupported on a platform scales 24. The overfiow line 14 is connected to a 3" perforated pipe 25 arranged about 6 ft. from the bottom of the settling tower C. An overflow line 26 is provided for discharging the refined. oil from the upper end of the tower and a drain connection 27 is provided for removing any' settled material from the lower end of the tower.

In refining a gasoline product according to the present invention in the apparatus illustrated, the tower A- is charged with a caustic alkali solution and the tower B is.

charged with a caustic alkali solution in which hypoz'hlorite is formed by the introduction of'chlorine. The tower A may be charged with a solution .made up with'about 800 gals. of water and about 700 to 725 lbs. of caustic soda. up by melting down solid caustic soda with steam in the usual way, adding the necessary volume of water, and cooling the solution to a temperature of from about C. to 80 F. before introduction into the tower. The caustic alkali solution employed in the tower B may be of similar composition. Before starting the ow of gasoline through the This solution may be made .lun

lio

towers, chlorine is introduced into the tower B from the liquid chlorine container 17.

Initially, about 50 lbs. of chlorine may be.

run in over a period of 30 minutes, and as the refining opera-tion continues additional amounts of chlorine may be run in from time to time as required. i The chlorine may be added without interrupting the refining operation. It is generally convenient and satisfactory to run in about 50 lbs. of chlorine at a time over a period of about 30 minutes. The amount ofchlorine introduced is measured by the difference in weight on the scales 24. The chlorine is introduced by opening the needle valve 27 and the globe valve 19, and the flow is regulated by the expansion valve 21. Except during the periods when chlorine is being introduced, the needle valve 27 and the stop valve 19 are kept closed. In connection with a charge lof the caustic soda solution of the amount and character just described it is convenient io employ cylinders containingr about 150 lbs. of liquid chlorine. 80()` gals. ofthe caus- -tic soda solution described will absorb approximately 450 lbs., orthree cylinders, of

liquid chlorine when used in carrying out the refining process of the present invention.

After the towers A and B have been charged with the caustic alkali solution and ofter the introduction of the initial amount of chlorine into the solution in the tower- B, the gasoline, or otheroil, to be refined is pumped successively through the towers A, B and C. In the towers A 'and B the gasoline is sprayed through the treating solii,

tions .and intimatelycontacted therewith, pressure being maintained sufficient to force the gasoline through each tower and to distribute it through the treating solutions in the towers. l The tower C gradually fills with gasoline and the refined gasoline product overflows through pipe 26. With a caustic soda solution of the amount and character previously described in tower A, the operation'can usually be continued for several.

weeks before this solution needs to be replaced or replenished.' A convenient test is to withdraw a portion of the gasoline from the test cock 5 and agitate .it with a lead acetate solution. If a. black precipitate appears the caustic alkali solution in tower A should be replaced or replenished. Chlorine is introduced into the caustic alkali, solution in tower B from time to time as required to produce a'jsweet product. If a test sample withdrawn from the sample cock 15 gives a positive doctor test it indicates that additional chlorine is required. After about 450 lbs. of chlorine have been introduced into a caustic soda solution of the amount and character previously described, the solution is4 usually discharged and replaced with .freshsolutiom The caustic alkali content of the treating solution in .tower B may, however, be partially replaced from time to time.

Where the vgasoline contains appreciable amounts of hydrogen sulfide or of other objectionable constituents which will react with caustic alkali, the gasoline is pumped first through tower A and thence to tower B, but, in the treatment of gasoline free from appreciable quantities of such constituents, the gasoline is pumped directly through tower Bl While the invention has been described particularly in connection with the treatment of gasoline, especially casinghead gasoline and natural gas gasoline, in which appl'ication it is of particular advantage, 1t will be apparent that the invention is of more or less general application in the treatment of hydrocarbon `oils and distillates which are susceptible to refining treatment with aqueous hypochlorite solutions.

I claim: A

1. An improved method of refining hydrocarbon oils in a continuous manner which comprises passing the oil through a body of aqueous hypochlorite solution containing an caustic into the solution to maintain the alkali in excess as the reaction progresses, and introducing chlorine at a oint remote from that at which the alkali 1s introduced but in the proximity of the point at which the oil is introduced, whereby additional quantities of hypochlorite are formed and the oil is subjected to that portion of the solution containing the highest concentration of hypochlorite first.

3. An improved method of refining hydrocarbon oils in a continuous mannerv which comprises passing the oil through a relatively long column ofv aquedus hypochlorite solution containing an excess of caustic alkali, introducing fresh caustic at one end of the column to maintain the alkali in excess as the reaction progresses, introducing chlorine at the -other end of the column nearest the point at which the oil is introduced, whereby the oil is subjected to tlat est concentration of hypochlorite first.

4.` An improved method of relining'hydrocarbon oils in a continuous manner which comprises passing the \oil first through a column of caustic alkali solution, then passloo' ing 'th'e oil through a column of an aqueous point at which the oil is introduced, whereby hypochlorite solution containing an excess the oil is subjected to that part of the soluof caustic alkali, introducing fresh 'caustic tion containing the highest concentration of 10 alkali into one end of the hypochlorite hy ochlorite rst. f

column to maintain the alkali in excess as l Fn testimony whereof I aiiix my signature.

the reaction progresses, introducing chlorine at the other end of the column nearest the HARRISON O. PARKER. 

